Hi audio incubator,
This is a simple and powerful idea that was suggested to me by audio
tools developer Joa Ebert of Hobnox last year (no connection to this
group's work) and I want to share it here. I think it could have a lot
of value and seems relatively easy to implement.
JavaScriptCueNode (new feature)
It is very useful to be able to have an audio scheduler cue the
invocation of some arbitrary code at a specific point on the audio
timeline, with no accompanying audio output.
Use cases:
- control some other piece of the application in synchrony with what
is happening in the audio at that point. (Example: make some
graphical element highlight in time to a musical beat, as in Drum
Machine demo)
- generate a new section of audio experience that smoothly extends the
current one before it ends (Example: dynamic generation of loops in a
gaming experience or as in Drum Machine demo)
Such functions are easiest to drive from the audio framework, instead
of having the rest of the app try to trigger itself at the exact
correct moment or interval. For example, look at the schedule()
function in the Drum Machine demo, and the somewhat tricky time
calculations and setTimeout() calls that it has to perform to loop/
advance the groove and draw the playhead. This would be much easier
to code if it were called on a rhythmic basis coming out of the audio
engine itself.
Such a node can be simply realized in the API as something similar to
a JavaScriptAudioNode but with zero outputs, and which exposes a
noteOn() function to schedule its occurrence. Something like:
interface JavaScriptCueNode : AudioNode {
attribute EventListener onnoteprocess;
void noteOn(in float when);
}
... . . . Joe
Joe Berkovitz
President
Noteflight LLC
160 Sidney St
Cambridge, MA 02139
phone: +1 978 314 6271
http://www.noteflight.comhttp://joeberkovitz.com